Negative air machines clean the air and help stop the spread of airborne contaminants in indoor spaces. Also called air scrubbers, they have higher airflow and clean air more efficiently than air cleaners. Negative air machines can be placed in a space to filter and recirculate air within that space. They can also be connected to flexible ducting to exhaust contaminated air out of a space, which is known as negative-pressure air cleaning. Industrial-grade negative air machines remove dust, lead, mold, debris, and other contaminants from the air in abatement, restoration, construction, and demolition applications. Medical-grade negative air machines remove pathogens, allergens, and other contaminants from the air in virus-containment and patient-isolation applications in medical facilities.